Fiber Channel over Ethernet (FCoE) is a technology used for transporting Fiber Channel (FC) frames over Ethernet, which is currently being standardized at the Technical Committee for Fiber Channel (T11) of the International Committee for Information Technology Standards (INCITS). The transported FC frames are used based on an FC architecture for storage networking purposes. The FCoE technology replaces the FC physical (FC-0) and FC coding (FC-1) layers of the FC architecture with the Ethernet physical and Media Access Control (MAC) layers of the Ethernet architecture without altering the FC framing (FC-2) layer and higher layers. Using the FCoE technology, the FC frames and standard Ethernet frames can be transported independently in the network. Accordingly, the FC frames are mapped over Ethernet frames and then transmitted on Ethernet links, which provides substantially seamless integration between FC based networks and Ethernet based networks. The FCoE technology can be used for server Input/Output (I/O) consolidation for FC-based storage area networks (SANs), which are widely used in enterprise data centers, and potentially for establishing a unified network infrastructure for data centers based on Ethernet.
A plurality of FCoE switch architectures have been introduced to implement FC switching functions and Ethernet bridging functions and to support an FCoE Initialization Protocol (FIP) according to Rev 1.01 for Fiber Channel Backbone (FC-BB-5) of the INCITS T11, published Jun. 10, 2008, which is incorporated herein as if reproduced by its entirety. In one architecture, an FCoE switch, also referred to as an FC Forwarder (FCF), comprises a plurality of components interconnected via a crossbar with centralized arbitration. For instance, the FCoE switch may be configured as described in a white paper by Cisco published 2008 and entitled “Cisco Nexus 5000 Series Architecture: The Building Blocks of the Unified Fabric,” which is incorporated herein by reference as if reproduced by its entirety. In another architecture, an FCoE switch comprises an Ethernet switch configured with built-in FC forwarding functions. For instance, the FCoE switch may be configured in N_Port Virtualizer (NPV) mode as described in Mellanox Product Brief, 3076PB Rev 1.0, entitled “BridgeX™ Silicon 10/20/40 Gb/s InfiniBand to 10 GigE and 2/4/8 Gb/s FC Gateway,” which is incorporated herein by reference as if reproduced in its entirety. In any event, the FCoE switch may comprise a plurality of FCoE ports that support standard Ethernet frames and Ethernet-encapsulated FC frames, which may be referred to as FCoE frames and identified by an Ethertype in the frame header. The FCoE switch may also comprise a plurality of FC ports that supports native FC frames.
Typically, the standard Ethernet frames may be received on an FCoE port and then forwarded according to the Institute of Electrical and Electronics Engineers (IEEE) 802 Ethernet standard. Further, the FCoE frames may be received on the FCoE port, de-capsulated to obtain the FC frames, and then forwarded, for instance according to Rev 0.50 for Fiber Channel Framing and Signaling (FC-FS-3) of the INCITS T11, published Jun. 13, 2008, and/or Rev 8.0 for Fiber Channel Switch Fabric (FC-SW-5) of the INCITS T11, published Nov. 22, 2008, both of which are incorporated herein as if reproduced by their entirety. The FC frame received from an FCoE port and de-capsulated may also be encapsulated in an Ethernet frame and forwarded to another FCoE port.
The FCoE architectures described above may be based on new chip designs and may not make use of existing Ethernet switches. As such, they require replacing or modifying some of the currently used network components. Further, combining available existing Ethernet-to-FC bridge chips with Ethernet switches to support FC ports and obtain FCoE switches may be exceedingly difficult.